THE NILE DAMS AND RESERVOIR. 553 



are, of course, enormously increased. It will be recognized at once, 

 therefore, that, as in the summer months the whole flow of the Nile is 

 arrested and thrown into the aforesaid canals, the old barrage will 

 always remain the most important work connected with the irrigation 

 of Egypt. It was constructed under great difficulties by French engi- 

 neers, subject to the passing whims of their Oriental chiefs. About 

 fifteen years elapsed between the commencement of the work and the 

 closing of all the sluices, and another twenty years before the structure 

 was sufficiently strengthened by British engineers to fulfil the duties 

 for which it was originally designed. All the difficulties arose from the 

 nature of the foundations, as the timber sheet piling wholly failed to 

 prevent the substructure from being undermined by the head of water 

 carrying away the fine sand and silt upon which the barrage was built. 

 At Asyut, cast-iron sheet piling was used, as will hereafter be described. 

 It is impossible to say what the cost of the old barrage has been from 

 first to last, but probably nearly ten times that of the recently-com- 

 pleted Asyut Barrage. Forced labor was largely employed in its con- 

 struction, and at one time 12,000 soldiers, 3,000 marines, 2,000 laborers, 

 and 1,000 masons were at work at the old barrage. 



In connection with the Nile Reservoir, subsidiary weirs have been 

 constructed below the old barrage to reduce the stress on that structure. 

 The system adopted was a novel one, reflecting great credit on Major 

 Brown, Inspector-General of Irrigation in Lower Egypt. His aim was 

 to dispense almost entirely with plant and skilled labor; and so, with- 

 out attempting to dry the bed of the river, he made solid masonry blocks 

 under water, by grouting rubble dropped by natives into a movable 

 timber caisson. Both branches of the Nile were thus dammed in three 

 seasons, at a cost, including navigation locks, of about half a million 

 sterling. Many other subsidiary works have been and will be con- 

 structed, including regulators, such as that on the Bahr Yusuf Canal. 



Asyut Barrage. 



By far the most important of the works constructed to enable the 

 water stored up in the great reservoir to be utilized to the greatest 

 advantage is the Barrage across the Nile at Asyut, about 250 miles 

 above Cairo, which was commenced by Sir John Aird and Co. in the 

 winter of 1898, and completed this spring. As already stated, in gen- 

 eral principle this work resembles the old barrage at the apex of the 

 Delta; but in details of construction there is no similarity, nor in 

 material, as the old work is of brick and the new one of stone. 



The total length of the structure is 2,750 feet, or rather more than 

 half a mile, and it includes 111 arched openings of 16 feet 1 inches 

 span, capable of being closed by steel sluice gates 16 feet in height. 

 The object of the work is to improve the present perennial irrigation of 

 lands in Middle Egypt and the Fayoum, and to bring an additional 



